This invention relates to an article useful for insulating metallic objects from ground contact. More specifically, it relates to an insulative wedge or shoe that is adapted to be attached to the end of a portion of a metallic frame or rail to enable the support of the metallic frame or rail in the earth in a state in which the frame or rail is electrically insulated from ground contact.
The development of pristine real estate and the maintenance of developed real estate often entails work by craftsman in several of the known trades, such as electricians, plumbers, linesmen, cable television installers, telephone installers, sewer lines, and natural gas lines, in addition to operators of heavy earthmoving equipment. It is commonplace for various conduits to be located in a subterranean environment, such as in the cases of buried pipes and wires.
A cable rack is a structural support framework which may exist in any configuration desired by the user. Cable racks are used to support cables and wires in a location which maintains their functionality while at the same time supporting them away from an area in which work, such as excavation, is carried out. To cite but one example, telecommunications companies drive steel bars directly into the ground in order to provide a vertical beam from which various wares, including cables may be hung. Such a practice is dangerous insomuch as the possibility exists that a steel bar so driven may on occasion strike an electrical supply line and pierce through its insulation, thus providing an effective electrical contact between the contents of a cable so breached and the steel bar. If a person is holding such a steel bar while it pierces such insulation, the person may become instantly in contact with an electrical potential of lethal electromotive force.
As a measure of safety, some telecommunications companies specify that a person who drives such bars into the ground must wear rubber gloves.
The prior art has addressed electrically insulating various metallic objects. For example, Re-reisve U.S. Pat. No. 26,779 discloses a street boundary post with a hollow space opening at least upwards, and having a holding arrangement for a rod-type snow sign. U.S. Pat. No. 5,022,618 provides a mailbox support apparatus comprising: a) a ground mount stake; b) a hollow post member of greater diameter than the ground mount stake, the hollow post member having a first open end and a second open end remote from and parallel to the first open end; c) spacer members detachably mountable upon the ground mount stake and sized to provide a pressure fit of the hollow post member upon the ground mount stake when the ground mount stake with the spacer members mounted thereon is longitudinally inserted into the first open end of the hollow post member; d) a mounting plate; e) a means for attaching the mounting plate to the second open end of the hollow post member; and f) a means for attaching the mounting plate to a bottom of a mailbox. U.S. Pat. No. 5,755,431 teaches a mounting fitting for securing a hollow post having an inner surface to a stake having a cross sectional configuration defining an outer surface, the mounting fitting comprising: a) a first member having an inner surface defining an aperture, in which the aperture includes a first leg and a second leg formed about a first axis and a third leg and a fourth leg formed about a second axis, and in which the first and second axes intersecting at a center, and in which the first, second, third, and fourth legs each including a terminal end remote from the center, the first member further including first sizing means for elastically deforming the inner surface and enlarging the aperture whereby the first member slidably accommodates stakes of varying sizes, the first sizing means including a slot formed in the inner surface; and b) a second member connected to the first member, the second member defining a peripheral surface adapted to be engageable with the hollow post to frictionally couple the hollow post to the mounting fitting.
However, of all the devices in the prior art, none is suitable for enabling the support of a metallic vertical beam portion of a cable rack or other framework in an insulated condition from the ground. Further, the prior art does not provide a means by which existing cable rack support framework may be rendered to have its end portion supported by the ground in an insulated condition. Further, the prior art does not provide a means by which an existing cable rack supporting framework may be conveniently pounded into the ground while being in an insulated condition with respect to the ground, which means is provided with a feature that greatly reduces or eliminates the propensity for breaching underground conduits, such as cables and pipes. However, by my invention, there is now available a device which provides the aforesaid means, as well as other advantages and features, which will become apparent to those skilled in the art after reading and understanding the contents of this specification.
The present invention provides an insulative wedge article for attachment to the ends of linear metallic wares. An article according to the invention comprises: a base portion and a clamping portion. The base portion exists substantially in the shape of a rectangular solid, and has a length dimension, a width dimension, a thickness dimension, a top surface, a bottom surface, a first end portion, and a second end portion. According to a preferred form of the invention, the top surface and the bottom surface taper towards one another in an intersecting orientation directed towards the first end portion. The second end portion of the base portion comprises a planar ledge of substantially rectangular dimensions having longest and shortest sides, wherein the length dimension of the planar ledge extends in the same direction as the length dimension of the base portion, and wherein the width dimension of the planar ledge extends in the same direction as the width dimension of the base portion. The planar ledge portion has a thickness dimension which is less than the thickness dimension of the base portion. The planar ledge comprises at least one locator block disposed thereon, and the ledge spans the entire width dimension of the base portion, and spans at least 25% of the length dimension of the wedge. The second end portion further comprises a plurality of fastener bosses disposed about the outer perimeter of the planar ledge along each of its longest sides, and the base portion further including a locator well in its top surface portion. The clamping portion exists substantially in the shape of a rectangular solid, and has a length dimension, a width dimension, a thickness dimension, a top surface, a bottom surface, a first end portion, and a second end portion. The bottom surface portion of the clamping portion includes at least one depression that is adapted to receive the at least one locator block. The first end portion of the clamping portion includes a tongue portion which protrudes lengthwise from its first end portion. The tongue portion further comprises a hook means which is adapted to connectively engage the locator well on the base portion. The clamping portion further comprises a plurality of fastener bosses disposed about the outer perimeter of each of its longest sides. The tongue portion is engaged in the locator well to provide an insulative wedge according to the invention.